/*
silverPDF is sponsored by Aleyant Systems (http://www.aleyant.com)

silverPDF is based on PdfSharp (http://www.pdfsharp.net) and iTextSharp (http://itextsharp.sourceforge.net)

Developers: Ai_boy (aka Oleksii Okhrymenko)

Permission is hereby granted, free of charge, to any person
obtaining a copy of this software and associated documentation
files (the "Software"), to deal in the Software without
restriction, including without limitation the rights to use,
copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the
Software is furnished to do so, subject to the following
conditions:

The above information and this permission notice shall be
included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR SPONSORS
BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
OTHER DEALINGS IN THE SOFTWARE.

*/
#region PDFsharp - A .NET library for processing PDF
//
// Authors:
//   Stefan Lange (mailto:Stefan.Lange@pdfsharp.com)
//
// Copyright (c) 2005-2008 empira Software GmbH, Cologne (Germany)
//
// http://www.pdfsharp.com
// http://sourceforge.net/projects/pdfsharp
//
// Permission is hereby granted, free of charge, to any person obtaining a
// copy of this software and associated documentation files (the "Software"),
// to deal in the Software without restriction, including without limitation
// the rights to use, copy, modify, merge, publish, distribute, sublicense,
// and/or sell copies of the Software, and to permit persons to whom the
// Software is furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included
// in all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
// THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER 
// DEALINGS IN THE SOFTWARE.
#endregion

#define VERBOSE_

using System;
using System.Diagnostics;
using System.Collections;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.IO;
using PdfSharp.Drawing;
using PdfSharp.Internal;

using Fixed = System.Int32;
using FWord = System.Int16;
using UFWord = System.UInt16;

namespace PdfSharp.Fonts.TrueType
{
  /// <summary>
  /// The indexToLoc table stores the offsets to the locations of the glyphs in the font,
  /// relative to the beginning of the glyphData table. In order to compute the length of
  /// the last glyph element, there is an extra entry after the last valid index. 
  /// </summary>
  internal class IndexToLocationTable : TrueTypeFontTable
  {
    public const string Tag = TableTagNames.Loca;

    internal int[] locaTable;

    public IndexToLocationTable()
      : base(null, Tag)
    {
      DirectoryEntry.Tag = TableTagNames.Loca;
    }

    public IndexToLocationTable(FontData fontData)
      : base(fontData, Tag)
    {
      DirectoryEntry = this.fontData.tableDictionary[TableTagNames.Loca];
      Read();
    }

    public bool ShortIndex;

    /// <summary>
    /// Converts the bytes in a handy representation
    /// </summary>
    public void Read()
    {
      try
      {
        ShortIndex = this.fontData.head.indexToLocFormat == 0;
        this.fontData.Position = DirectoryEntry.Offset;
        if (ShortIndex)
        {
          int entries = DirectoryEntry.Length / 2;
          Debug.Assert(this.fontData.maxp.numGlyphs + 1 == entries,
            "For your information only: Number of glyphs mismatch in font. You can ignore this assertion.");
          this.locaTable = new int[entries];
          for (int idx = 0; idx < entries; idx++)
            locaTable[idx] = 2 * this.fontData.ReadUFWord();
        }
        else
        {
          int entries = DirectoryEntry.Length / 4;
          Debug.Assert(this.fontData.maxp.numGlyphs + 1 == entries,
            "For your information only: Number of glyphs mismatch in font. You can ignore this assertion.");
          this.locaTable = new int[entries];
          for (int idx = 0; idx < entries; idx++)
            locaTable[idx] = this.fontData.ReadLong();
        }
      }
      catch (Exception ex)
      {
        throw ex;
      }
    }

    /// <summary>
    /// Prepares the font table to be compiled into its binary representation.
    /// </summary>
    public override void PrepareForCompilation()
    {
      DirectoryEntry.Offset = 0;
      if (ShortIndex)
        DirectoryEntry.Length = this.locaTable.Length * 2;
      else
        DirectoryEntry.Length = this.locaTable.Length * 4;

      this.bytes = new byte[DirectoryEntry.PaddedLength];
      int length = this.locaTable.Length;
      int byteIdx = 0;
      if (ShortIndex)
      {
        for (int idx = 0; idx < length; idx++)
        {
          int value = this.locaTable[idx] / 2;
          this.bytes[byteIdx++] = (byte)(value >> 8);
          this.bytes[byteIdx++] = (byte)(value);
        }
      }
      else
      {
        for (int idx = 0; idx < length; idx++)
        {
          int value = this.locaTable[idx];
          this.bytes[byteIdx++] = (byte)(value >> 24);
          this.bytes[byteIdx++] = (byte)(value >> 16);
          this.bytes[byteIdx++] = (byte)(value >> 8);
          this.bytes[byteIdx++] = (byte)value;
        }
      }
      DirectoryEntry.CheckSum = CalcChecksum(this.bytes);
    }
    byte[] bytes;

    /// <summary>
    /// Converts the font into its binary representation.
    /// </summary>
    public override void Write(TrueTypeFontWriter writer)
    {
      writer.Write(this.bytes, 0, DirectoryEntry.PaddedLength);
    }
  }
}